Ultrasonic Coatings
Following the introduction of ultrasonic spray nozzles in the 1970s, ultrasonic coating technique began to be used and its application in many industries such as textile,
nanomaterial, touchscreen production and glass coating has become widespread, especially in recent years.
Ultrasonic technology, which is based on converting high frequency sound waves into mechanical energy, has been adopted more and more by the coating manufacturers.
What Is Ultrasonic Sound Wave?
The term ultrasonic derives from the combination of two words in Latin, ultra (meaning “beyond”) and sonic (meaning “sound”), and is used to refer to vibrations of frequencies that exceed the audible capacity of humans, which is higher than 20 kHz.
Many animals such as dogs, frogs, dolphins, praying mantis and bats make use of ultrasonic sound waves to fulfill their vital functions. For instance, over 1,100 species of bats utilize ultrasonic frequencies to find food in the dark via echolocation and use the insects they detect as tucker during the flight.
Areas of Usage of Ultrasonic Sound Waves
Ultrasonics is the study of ultrasonic sound waves and constitutes a part of sound studies, a branch of physics based on wave motions. Ultrasonic applications date back to 1880s. Many industries such as communication, food, textile, and, most notably, medicine have earned
significant achievements thanks to ultrasonics.
Ultrasonic technology does not only enable to detect the size and position of fetus and birth defects, but also makes it possible to measure the exact depth of scars in human body.
One of the most important advantages of ultrasonic applications is that it removes any risk that might be caused by X-Ray imaging and incisions. Moreover, strong shock waves generated by micron droplets that are formed via ultrasonic waves are used to detect and eliminate cancer cells and treat gallstone and kidney stones, as well. Ultrasonic sound waves are also frequently utilized in navigation.
Through the application of audible and ultrasonic sound waves, it is possible to detect the location of a distant, moving obstacle. When the obstacle moves toward the source, the frequency of the reflected wave increases; and when the obstacle moves away from the source, the frequency of the reflected wave decreases.
This technique is quite functional when it comes to locating and tracking submarines and sea mines. Compared to sound waves, ultrasonic waves are particularly favorable in underwater applications as higher frequencies equal to shorter wavelengths, which enable the vessels to travel greater distances.
How Ultrasonic Nozzles Work
The ultrasonic nozzle tip, which contains piezoelectric transducers that form vibrations at high frequency, provides a rapid coating by creating an up and down motion several thousand times per second. A thin film of liquid that is applied to the ultrasonic nozzle tip leads to the formation of capillary waves.
The amplitude of these waves can be regulated by the ultrasonic generator and once the
capillary waves are no longer able to support themselves, they form micron-sized liquid droplets. Unlike pressure nozzles, ultrasonic nozzles are not based on a system in which high pressure is applied to get the liquid through a small orifice.
Instead, without having to apply pressure, liquid transition is obtained through a large orifice and the liquid is atomized as a result of ultrasonic vibrations in the nozzle. High-strength titanium alloys that were used during the fabrication of nozzles render them remarkably resistant to chemical reactions. The electrically active elements are contained in a sealed housing that prevent external factors from harming the nozzle components.
The nozzles are designed in a way that liquid only comes into contact with the titanium inside of them.
Industries that Apply Ultrasonic Coating Technique
One of the industries where ultrasonic coating technique is frequently applied is glass industry, which can be divided into sub-branches such as lens, touchscreen and solar panel production. Ultrasonic spray coating comes out as an alternative to powder and pressure spraying and thus it is preferred particularly in float glass industry. Since this process does not require high vacuum, ultrasonic coating is widely used in solar panel production.
Besides, this technique is utilized in the production of items such as microscope, protective glass and camera and telescope lenses. Ultrasonic coating technique is also employed in the production of nano and submicron scale thin film coatings. Polymers and dyes, which can be classified within the realm of thin film coatings are arranged in medical ultrasonic
biosensors. Ultrasonic coating system allows for an easy control over flow rate and deposition volume and therefore facilitates the formation of a thin and uniform layer.
Advantages of Ultrasonic Coating Technique
Ultrasonic spray technology has replaced conventional coating techniques due to its innovative aspects. Ultrasonic coatings stand out for being more easily controllable than conventional coatings. Since ultrasonic coatings require minimum pressure and use low-velocity spray, having control over the coating is much easier than traditional methods such as dip and spin coating.
As spraying process takes place at a low velocity, overspray and bouncing can be prevented and the amount of waste can be reduced, therefore it provides an affordable and environmentally friendly coating. Nozzles used in the process are compatible with other nozzles that have different functions.
Furthermore, since they can function under very low pressure, nozzles are non-clogging and selfcleaning. Ultrasonic spray coatings allow for new application techniques. Unlike many coating methods, ultrasonic nozzles perform well in processes in which low flow
rates are required.
Furthermore, even when spray process is interrupted, all particles remain suspended in a regular manner. This brings out a uniform dispersion of particles in thin layers.
The Future of the Coating Market
Ultrasonic coatings market has recently achieved a considerable growth around the world, particularly in developed countries. Many large companies in the industry have acquired smaller ones and expanded its product portfolios.
According to a report published in 2015, 48.6% percent of ultrasonic coating production takes place in North America, followed by Asia and Europe, 29% and 17%, respectively. Since sensor, glass, textile and fuel cell industries that utilize ultrasonic coating tend to grow, there is a higher possibility for relevant companies to grow in the future as well.
The global ultrasonic coating market size was 15.32 billion USD in 2022 and it is expected
to reach 27.43 billion USD in 2028.
References
• https://www.sono-tek.com/ultrasonic-coating/ultrasonic-spray-benefits/
• https://www.sono-tek.com/ultrasonic-coating/how-ultrasonic-nozzles-work/
• https://www.britannica.com/science/ultrasonics
• https://flypaper.soundfly.com/discover/ultrasonic-animals-that-vocalize-at-frequencies-beyond-our-hearing-range/
• https://cheersonic-liquid.com/en/portfolio-items/ultrasonic-spray-coating-system/
• https://cheersonic-liquid.com/en/medical/biological-sensor-coating/
• https://microspray.com/ultrasonic-spray-nozzles-work/
• https://rivercountry.newschannelnebraska.com/story/46355377/ultrasonic-coating-systems-market
• businessresearchinsights.com/market-reports/ultrasonic-coating-systems-market-100279
• Görseller / Images by: pixabay.org
Compilation and Translation by: Murat Soygür
